There exists a cosmetic treatment such as iontophoresis where a weak electric current is applied to skin to effectively introduce, for example, water-soluble active ingredients into the skin. The stratum corneum has a barrier function that prevents intrusion of foreign substances. Therefore, for example, when a lotion is simply applied to the skin, water-soluble vitamin C in a lotion is blocked by the barrier function and cannot penetrate into a deep layer of the skin.
Meanwhile, iontophoresis, for example, enables active ingredients of a lotion to pass through a barrier layer and penetrate into a deep layer of skin with the use of electric power.
To receive a cosmetic treatment based on iontophoresis, it is normally necessary to go to a cosmetic clinic or to purchase a cosmetic device dedicated to iontophoresis (see, for example, patent document 1).
There also exists a method for controlling a pulse waveform output from an iontophoretic device depending on the purpose to improve the effect of iontophoresis (see, for example, patent document 2).